The weather radar says there is rain the whole of next week in Meghalaya. As far as Dawki river side today there is moderate rain but as days go by rain is forecasted. It might change too, allowing travel easily. So I personally feel you should keep a check on the weather and if safe travel accordingly. Any traveller staying in Meghalaya kindly do answer this question.
As per weather report, there are chances of rain in next week in Meghalaya and Dawki region. Sometimes rains will be continuous and may not give you better experience of your trip. Chances are high that water in Dawki may not look clear since it is raining, you may see the mud water. Best time to experience clear water is during monsoon season that is December to February.